Seven Nobel Prize-winning economists and eight former presidents of the American Economic Association have signed a letter to Congress and the president endorsing a gradual increase in the minimum wage to $10.10 per hour.

The letter urges lawmakers to enact a three-step raise of 95 cents a year for three years, which would mean a minimum wage of $10.10 by 2016, and then index it to protect against inflation. The increase would mean minimum-wage workers who work full-time all year would see a raise from their current salary of roughly $15,000 to roughly $21,000.

The economists supported legislative proposals in the House and Senate that also would raise the tipped minimum wage to 70 percent of the regular minimum.

"Let’s be clear: Our federal minimum wage of just $7.25, which has not budged in more than four years, is now a poverty wage. No American who works a full-time job should have to struggle to put food on the table or pay the bills,” said U.S. Sen. Tom Harkin, a Democrat and the chairman of the Senate Health, Education, Labor, and Pensions Committee. “All around the country, we’re seeing the impact of growing income inequality and stagnant wages on millions of American families. Raising the minimum wage will help narrow the income gap and enable millions of low-wage working Americans to make ends meet."

Harkin, added, "As the letter released by the Economic Policy Institute shows, economists and experts agree that raising the minimum wage isn’t just the morally right thing to do, it’s also the smart thing to do for our economy, sending $22 billion into the economy and adding 85,000 jobs over three years thanks to higher consumer demand. Now is the time for action."